# -*-coding utf-8 -*-

__project__ = 'le-bo16'
__file_name__ = 'homework14'
__author__ = 'hqDu'
__time__ = '2020-11-27 22:31'
__product_name = 'PyCharm'
# @fileName :homework14.py

print(not None)
print(None)

# 单例模式
# 异常类型